A variety of automated or semi-automated chemical analyzers are known which utilize cuvettes for the chemical testing of samples placed therein. Generally a predetermined amount of liquid sample, such as biological fluid, is placed in the cuvette which is then transported through the instrument. As the cuvette is being transported, the instrument dispenses a quantity of reagent into the sample and monitors the resulting chemical reaction. Such monitoring is generally accomplished through use of an optical means which views the fluid sample through optically transparent portions of the cuvette.
In order to simplify the loading of the cuvettes into the instrument and facilitate their handling by the instrument once so loaded, proposals have been made to provide the cuvettes in the form of a continuous integral strip. The individual cuvettes of the strip are designed to be relatively rigid but the strip itself is provided with sufficient flexibility to ease its transport through the instrument. Furthermore, by making the cuvettes in continuous strip form, they can be manufactured relatively inexpensively from suitable plastic material thereby permitting their disposal after sue. This is an important feature since it avoids the requirements for washing the cuvettes after use and avoids any possibility of crosscontamination of fluid samples which could cause erroneous test results. A proposed cuvette system designed to meet these requirements is disclosed in U.S. Pat. No. 4,263,256.
In commonly owned copending U.S. patent application Ser. No. 559,016 filed Dec. 8, 1983 entitled "Cuvette System For Automated Chemical Analyzer", a continuation of U.S. patent application Ser. No. 284,842 filed July 20, 1981, the disclosure of which is hereby incorporated by reference in its entirety herein, there is described a cuvette belt which comprises a matching pair of elongated, formed plastic strips which are joined together along corresponding faces thereof to form an integral belt. A series of regularly spaced chamber halves are formed transversely in each of the corresponding strip faces which define open-topped cuvette receptacles when the belt halves are joined.
As described, the cuvette belt is made by forming strip plastic material with a series of regularly spaced transverse (laterally extending) formed pockets so as to define two integral side-by-side belt halves. The formed strip is then divided longitudinally to separate the belt halves and the belt halves brought into register and joined together to form a completed cuvette belt.
Reference is also made to commonly owned copending U.S. patent application Ser. No. 746,231 filed June 18, 1985, entitled "Cuvette Belt Manufacture and Process", the disclosure of which application is hereby incorporated by reference in its entirety herein. In that application is disclosed an alternative method for making cuvette belts of the kind comprising a matching pair of plastic strips, each of which is formed with chamber halves and which are joined together to form an integral cuvette belt with the chamber halves aligned to form the cuvettes.
According to that method, two strips of plastic material are identically formed with a series of regularly spaced transverse formed pockets so as define two integral side-by-side mirror image belt halves. The two formed strips are brought into register and joined together to form a composite strip defining two integral mirror image cuvette belts joined together by their cuvette mouth ends. The composite strip is then divided longitudinally to separate the cuvette belts.
The present invention is concerned with a method of testing cuvette belts which is applicable to such belts in general while having particular applicability to the kinds of belts disclosed in the aforesaid copending applications.